Carbureter



C. l.. HAYFIELD.

' cARunETEa. V APPLICA'HQN FILED IUNE 2|, 19171 1,401,555, Patented Dec. 27, 1921.

UNITEDA STATES PATENT OFFICE.

CHARLES I. RAYFIELD, F CHICAGO, ILLINOIS.

GLRBUBETEB. t

To au whom it may concern:

Be it known that I, CHARLES L'. RAYFIELD, a citizen of the United States, residin at Chicago, in the county of Cook and tate of Illinois, have invented certain new and useful Improvements in Carbureters, of which the following is a specification.

One of the objects of my invention is to provide automatically controlled means in a carbureter for reducing the charge intake of internal com ustion engines, whereb especially to provide suitable qualities o fuel charges, at times of starting the engine when it is cold, to compensate' for the increase of viscosit of the fuel; the larger oxygen content o the cooled air; condensation of the charge, and other results produced by relatively low temperature.

Another object of my invention is to provide means in a carbureter, to automatically adjust the parts thereof, as the engine cools olf to atmospheric temperature, whereby suitable conditions will thereby be established to admit proper proportions of liquid fuel and air, appropriate for, and preliminary to starting of the engine, and parts, arranged to vary the valve adjustment, responsive directly to the heat evolved by operation of the engine.

And still another object ofmy invention is to provide a carbureter having operative parts adjusted to produce a quality of mixture suitable for given tem eratures of the engine, by affecting a valve or this purpose, and means, responsive to the heat given off bythe engine to modify they adjustment of said valve.

Other and more specific objects of my invention will become readily apparent, to persons skilled in the art, from a consideration of the following description when taken in conjunction with the drawing, which shows a central vertical section of a conventional representation of a` carbureter and a part of the exhaust pipe, with mythermoresponsive device partly inserted within the exhaust pipe, for varying the resistance to operation of the air admitting valve of the carbureter.

At the time of starting an internal combustion engine it iscolder,.of course, than ,c it is when it has been heated to a suieient operative temperature.

Srwitionbf Letters Patent Patented Dec.` 27, 1921. application mea :nine 21, 1917.` serial no. 176,187.

At such time the liquid fuel, such as gasolene, is below the temperature at which it is maintained during normal working operation of the engine. When the liquid fuel is cold it is more viscous than when it is warm. Therefore, the same uantity of such fluid will not pass throug a given orifice, under the same pressure,l as when it is heated to a higher temperature. It follows, then, that a smaller portion of fluid, or gasolene, passing through afixed orifice, other conditions being unchanged, will provide an attenuated or sub-normal mixture, of a quality below that required for Vnormal operation. When cold, the air is specifically heavier than when warm, therefore, a given volume of air Which will pass through a given orifice under a given pressure will be of greater mass than when it is warmer.r

It is the mass of air and not its volume that determines its oxygen content and it is the proportion of oxygen to hydrocarbon that determines the quality of mixture, and

In the accompanying drawin showing a I vertical section of the device, have illustrated one embodiment of my invention, for the purpose of clear disclosure, reserving, however, to myself, the right to change or vary the structure to any extent or in any direction,l within the scope of the appended claims.'

The casing 5 incloses the mix' chamber 6, .the float chamber 7 and the c amber 8, within which the temperature-responsive device 9 is contained. This chamber is separably secured to the main body part of the carbureter for convenient application to the engine. The casing 8 is threaded on the outside, as at 10, for a nut 11 whereby it may be screwed into a threaded orifice provided in the exhaust pipe 12, as the screwl threaded {iange 13 thereof, to a greater or less ldistance as may be desired so as to expose a greater -or less surface to the heating effect of the hot exhaust products `of combustion. When the casing 8 hasl been introduced to the proper extent within the exhaust pipe, the nut 11 is tightened and this helps to support the carbureter in position. The heat responsive device 9 in the casing 8, in this particular embodiment, takes the form of a bellows diaphragm, or diaphragm structure, capable of considerable, relative axial elongation and contraction. prisons air or other Huid having a critical temperature expansion.

I L The air intake opening 14 of the carbureter is normally closed by an air valve 15. The spring 16, which moves the valve toward closed position may be adjusted by the bearingfnut 17, which surrounds the valve stem 18, and by which the valve stem is guided. A supplemental spring 19 connects the valve 15 to the axially movable diaphragm' structure 9. This spring tends to close the valve, when the diaphragm structure is contracted, as shown, and in this respect it supplements theaction of the valve spring 16. The valve isl therefore yieldingly `held closed by the combined action of the springs 16 and 19 when the expansible medium, gas or air, within thedia-y phragm structure, is below a given temperature. When the imprisoned exp'ansible medium is heated, as'by the heat'emanating from an engine, and in this particular case by the lhot products of combustion passing through `the exhaust pipe, the diaphragm structure 9 will be expanded, thereby Vrelaxing the spring 19, by increase of heat and contracting itl by aY decrease of heat, which will consequently reduce and increase the stress with which the valve 15 is held closed. Thus when the spring is res is' the throttle.

laxed the valve 15 will be'more `easily operable b the suction 'effect ofthe engine and it wil be held more firmly toward closed position when the temperature of the engine is decreased by the contracting .eifect of the heat responsive structure. i

20 isi-the spraying nozzle of the carburelier, in communication with 'the liquidcontainin float chamber 7 by an open'ing 21. The need e valve 22may be used te control the flow of gasolene into the nozzle and 26 Primary air passages ,around the nozzle, are provided by the'openings 23, of which there may be any desired number of suitable sizes.

The float 24 controls the quantity, or level of the liquid fuel in the float chamber, as

usual in such devices.

Thev operation ofthe device-is as' follows z-When the engine is co1d,'or relatively cold, the air, 'or other expansible `fluids, or gas within the heat-responsive device 9, cool and contracted, causing contraction of this diaphragmstructure. The decrease in volume of the confined medium, resulting from the reduction of temperature,

' in coperation with the `external atmospheric pressure, will cause contraction of the diaphragm structure. This, of course, as heretofore explained, increases the tension of the spring 19. When the engine shaft is initially rotated, in the act of starting the en ine, it will, therefore, require greater suction to be produced by the engine to open the valve 15, to the same extent, as such ,operation is now opposed by the combined resistance imposed by the springs 16 and 19. Conse uently a mixture of suitable quality will e drawn into the cylinder,-

as'the air will be taken in largely through the primary air ports 23. After the engine has been operating for a while, its increased temperature will heat and expand the content of the heat-responsive member 9, caus-V ing the free end thereof to be moved downwardly, thereby reducing the tension of the spring 19, whereupon the air supply valve A15 will be more easily opened by the same suction, to supply the proper proportion of air for the normal running of the engine. By this means compensation is made for the reduced temperature of the engine, of the fuel and ofthe air, at the time of starting `and dui-in the time when the tem erature fof the engine is below that at which it is -of the auxiliary air valve 15. For the foregoingreasons the device serves as an automatic primer in which air is taken into the carburetor largely through the primaryair ports 23 until the engine has been pro erly started after which more or less air wi l be taken through the port controlled by the valve 15.l l

' While I have herein shown a single emiis bodiment of` my invention `for the purpose of clear disclosure, it is manifest that changes maybe made inthe general form and arrangement of the parts within the sco e of the appended claims.

aving described my invention, what I n claim is A- carbureter hav' an air' admitting valve, in combination wlth a heat-responsive 13o device, normally resisting the opening of hot gases exhaust from said engine, and a said valve, subject to be heated by the hot nut surrounding said casing for securing exhaust gases of an engine to reduce said it in adjusted position. 10 resistance; a casing,exterior1y threaded and In testimony whereof I hereunto set my surrounding said responsive device for in hand. y r

sertion to a. greater or less extent, within a threaded aperture in a conduit carrying the CHARLES L. RAYFIELD. 

